Crown-post.



\ EDMUND J. HUFF, JR., or PHILADELPHIA,PENNSYLVANIA, vAND FREDERIK.

"0F ST. GEORGE, NEW YORK To all whom t may concern.'

Be it known that we, EDMUND J. HUFF, Jr., and FREDERICK A. JOHNSTON, citizens of the United States, and residents of Philadelphia, county of Philadelphia, State of Pennsylvania, and St. George, county of Richmond, State of New York, respectively, have invented vcertain new anduseful Improvements in Crown-Posts, ofwhich the Ifollowing is a specification, reference being had to the accompanying drawings. l l

ur invention relates particularly p to crown-posts for securing artificial tooth, crowns upon natural tooth roots, to replace tooth-crowns lost by breakage or decay, and is especially directed to that class of crown-` posts which are sold separate or detached from the tooth-crown, and upon which the tooth-crown may be attached by cement.

The principal object of our invention is to provide a detached crown-post which combines simplicity and strength with ease of attachment to the tooth-crown.

Specifically stated, our invention comprehends a crown-post having a root shank widening into a flange forming `a circular body, from which extends an oppositely disposed crown shank having spaced anchorflanges intermediate of the body flange and its free end, and having notches disposed adjacent to its free end to form a terminal anchor head of less diameter than said intermediate flanges.

Our invention also includes all of the various novel features of construction and arrangement hereinafter more definitely specied.

In the accompanying drawings, Figure 1 is a side elevational view of a crown-post constructed in accordance with our invention, having its crown shank embedded in a tooth-crown which is shown' in section for convenience of illustration; Fig. 2 is a central vertical longitudinal sectional view of the crown-post per sataken transversely; Fig. 3 is an inverted plan view of the crownpot shown in Figs. 1 and .2; Fig. 4 is a horizontal transverse sectional view taken on the line 4-4 in Fig.` 2; Fig. 5 is a horizontal transverse sectional view taken on the line 5-5 in Fig. 2; Fig. 6 is a horizontal transverse sectional view taken on the line 6 6 in Fig. 2; and Fig. 7 is a fragmentary side CROWN-Pos1 Specification of Letters Patent.

tened' tapered :fiange 9 by fillets 15, having its edges 16 rounded, as best'shown inFig. 4, andhaving 'its sides provided with a ASSIGNORS T0 THE S. S.'.'WH-ITE DENTAL l MANUFACTURING COMPANY, 0F PHILADELPHIA,

PENNSYLVANIA, g

i elevational View. of amodiied form `of the crown-post shown in, Fig. 1.

.. l, OEFICEK.

. Patented Julyc, 1915. `appiieation'alaDecember15,1914. i seriamo. 877,287. Y i

'In said figures, the crown-post comprisesy the flange or body 9, from which projects, preferably in axial alinement, the oppositely directedroot shank 10 and the crownshank 12, respectively engageable"withv the natural tooth root (not shown)y and the'artificial tooth-crown-IS. j Y' y The root shank 10 is in theform ofaI flat- `pin vjoined with the body series of transversely disposed curved or dished grooves 17 forming the intermediate ribs 19.

The crown shank l2 is arranged to be embedded in the cement 20 contained in' the socket 21, `which is provided therefor in*` the tooth-crown 13 and which extends inwardly from the bottom 22 of the recess 23 in the base 24 of said tooth-crown. The crown shank 12 is provided with anchor fianges 25 and 26 disposed in spaced rela-` tion from each otherand from its free end and the body flange 9, and has flattened surfaces 29 and 30 respectively extending parallel with the axis 0f the shank between the bodv fiange 9 and anchor flange 25, and between the anchor fianges 25 and 26. Said crown shank 12 is also provided with notches 32 adjacent to its free end, forming fiat surfaces 33 extending obliq'uely inward toward said free end and providing an overhanging terminal head 35 of less diameter thanthe anchor fianges 25 and 26, and affordingv additional anchoragey at the extreme `end of said crown shank. It will be obvious that K by thus forming the` terminal anchorage head 35 the crownshank 12 may be fitted inv the socket 21 in thev tooth-crown, and may extend to the bottom thereof, or in very closely adjacent relation thereto, without in any way interfering with the fillets 36 which are necessarily formed therein in the manufacture of such artificial teeth,`and therefore such construction of the crown shank 12 is advantageous, not only that the crown-post loo may be attached to the tooth-crown without grinding out the socket 21, but less care is required to reduce the fillet 36 in the manufacture of such teeth. p

Although, as shown in Figs. 1 to 6, inclusive, the flat surfaces 29 and 30 .of the crownpost eXtend in planes parallel with, or in planes normal to, the plane of the root shank 10, it is to be understood that said liat surfaces may be otherwise disposed, for instance, as shown in Fig. 7, wherein the flat surfaces 39 and 40 of the root shank 41 are disposed in oblique relation to the plane of the crown shank 42.

We do not desire to limit our invention to the precise details of construction and arrangement herein set forth, as it is obvious that various modifications may be made therein Without departing from the essential features of the invention as defined in the appended claims.

Having thus described our invention, we claim:

1. A crown-post comprising abody flange, a root-shank and a crown-shank having anchor flanges spaced intermediate of its free end and said body flange, and having undercut surfaces adjacent to its free end forming Copies of this patent may be obtained for ve cents each, by addressing the a head of less diameter than said anchor flanges, and providing retaining shoulders. 2. A crown-post comprising a body iange, a root shank, and a crown shank having an chor flanges spaced intermediate of its free end and said body fiange, and having oppositely disposed relatively angular undercut surfaces adjacent to its free end forming a head of less diameter than said anchor flanges, and providing retaining shoulders.

ln testimony whereof, We have respectively hereunto signed our names the 10th day of December, A. D., 1914, and the 11th day of December, A. D., 1914.

EDMUND J. HUFF, JR. Witnesses:

WILLIAM J. RUSSELL, CLIFTON C. I-IALLOWELL.

FREDERICK A. JOHNSTON.

Witnesses: c

STEPHEN M. BROUGIIAM, H. S. BEDELL.

Commissioner of Patents,

Washington, D. C. 

